In process automation engineering and in production automation engineering, field devices are often used to record and/or influence process variables. To record process variables measuring devices or sensors are used, such as level measuring devices, flowmeters, pressure and temperature measuring devices, pH/ORP measuring devices, conductivity meters etc., with such devices measuring the process variables level, flow, pressure, temperature, pH value or conductivity respectively. Actuators, such as valves or pumps, via which it is possible to alter the flow of a liquid in a pipe section or the level in a vessel, are used to influence process variables.
In principle, the term field device refers to any device that is used close to the process and delivers or processes information that is relevant to the process. In addition to the measuring devices/sensors and actuators mentioned above, the term field device is also generally used to describe units that are directly connected to a fieldbus and used for communication with the higher-order units, such as remote I/Os, gateways, linking devices and wireless adapters.
The field devices must be parameterized or configured using parameters before the field device is commissioned and to service the field device when the field device is in operation at the site of the field device operator. Operating devices are used for configuration, particularly to read and/or write parameters. Such operating devices are generally implemented on a communication unit that is separate from the field device, such as an operating device for example, and communicate with the field device via an interface.
For this, operating devices are known from the prior art that relay a relatively high resolution of information via a comparatively large display, and enable very precise selection of individual information via a pointing device, such as a mouse or a trackball. This resulted in user interfaces with a large information content and a high level of detail. Tree and menu structures have proven to be a particularly convenient display format for the operation (configuration and/or maintenance) of field devices up to now. Here, the procedure is based on explicitly selecting objects with the pointer device in order to run functions on this object. In this way it was possible to navigate through structures to get to the appropriate position.
Nowadays, more and more mobile operating devices are in use that are fitted with a touch-sensitive input and/or display area, such as a touchscreen. Such touch-sensitive input and/or display areas are typically operated by finger gestures. Due to the mobility of the operating devices, there are restrictions particularly with regard to the size of the display. Alongside this, the precise selection via a pointer device—which in this case is usually a finger—has become significantly more difficult.